Mm&#39;x-y metal composite functional material and preparation method thereof

ABSTRACT

An MM′X—Y metal composite functional material and a preparation method thereof; an MM′X—Y metal composite functional material, comprising the following components in percentage by volume: A% of M a M′ b X c  and B% of Y, wherein each of M and M′ is any one element of a transition group or an alloy of more than one element, X is any one element of IIIA group or IVA group or an alloy of more than one element, and Y is any one element of IB group, IIB group, IIA group or IVA group, or an alloy of more than one element, wherein the value range of a, b and c is 0.8-1.2, and the sum of A% and B% is 100%; the material is prepared through smelting, annealing, crushing, mixing, pressing and curing, etc.; the mechanical performance of the MM′X—Y metal composite functional material prepared according to the present invention is far higher than the traditional MM′X material; the prepared MM′X—Y metal composite functional material has an ideal magnetothermal effect, thus can be used as a magnetic refrigeration material; the method can prepare MM′X—Y metal composite functional materials with any size and shape according to actual requirements; the method is simple, and can be easily operated and realized.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the technical field of metal materials, and more particularly, to an MM′X—Y (M and M′ are transitional elements, and X is an element of IIIA group or IVA group) metal composite functional material and a preparation method thereof.

BACKGROUND OF THE INVENTION

Martensitic phase transition is an important diffusionless solid-state phase transition of crystal structure, and is a first-order transition. Martensite is formed in carbon steels by the rapid cooling of the austenite form of iron at such a high rate that carbon atoms do not have time to diffuse out of the crystal structure in large enough quantities to form cementite. The martensitic reaction begins during cooling when the austenite reaches the martensite start temperature and the parent austenite becomes mechanically unstable. As a result of the cooling, the face-centered cubic austenite transforms to a highly strained body-centered tetragonal form called martensite that is supersaturated with carbon. The shear deformations that result produce a large number of dislocations, which is a primary strengthening mechanism of steels. During this process, an increasingly large percentage of the austenite transforms to martensite until the lower phase transition temperature is reached, at which time the transition is completed. Martensitic transition materials are widely used for strengthening steels, toughening materials, reducing quenching deformations, improving shape-memory effect and enhancing super-elasticity. They're ideal functional materials.

For the huge structural difference between the martensitic phase and the parent phase, the martensitic transition process is usually accompanied with a drastic change of crystal structure. The aforesaid effect is also applied for shape-memory alloys. Namely, the material with a certain shape is cooled at a high temperature higher than the martensitic transition temperature (T_(M)), thereby forming a low-temperature martensitic phase. In this state, the material deforms under load. After being heated to the martensitic reverse transition temperature (T_(A)), it is restored to the original shape. It's difficult to improve the response frequency and sensitivity of traditional shape-memory alloys because their deformations are controlled by temperature and stress variation.

In recent years, researches have shown that the martensitic transition of some materials can be controlled by a magnetic field other than a temperature field and a stress field. These novel materials with ferromagnetic and thermo-elastic martensitic transition are called ferromagnetic martensitic transition alloys. Due to the coupling effect of the magnetic transition and the structural transition, the structure, the magnetic properties and the electric properties of the crystal are changed violently. As a result, the ferromagnetic shape-memory alloys present various functional effects such as shape-memory effect, magnetostriction effect, magneto-resistance effect, Hall effect and magneto-thermal effect, etc. These rich magnetic properties and potential application values make the ferromagnetic martensitic transition alloys become novel functional materials that attract wide attentions.

Presently, the largest family of the ferromagnetic martensitic transition alloys is the Heusler alloys, including Ni—Mn—Ga, Ni—Mn—Al, Ni—Mn—In and Ni—Mn—Sn. More recently, a novel MM′X (M and M′ are transitional elements, and X is an element of IIIA group or IVA group) ferromagnetic martensitic transition material (e.g., MnCoGe or MnNiGe) has been found by researchers. Through adjusting the compositions and preparing processes, the MM′X alloy also shows a magnetic-field-induced ferromagnetic martensitic transition. During the transition, a huge deformation of crystal structure and a magneto-thermal effect are achieved, and the phase transition temperature can be adjusted within a wide range. Thus, the MM′X alloy can be used as a multifunctional material (e.g., shape-memory material, negative expansion material and magnetic refrigeration material, etc.), and is considered as a new generation of ferromagnetic martensitic transition functional materials.

However, the huge deformation of crystal structure of the MM′X functional material during the martensitic transition process generates a large internal stress, making the MM′X functional material broken after the transition. Thus, the difficulty of forming and mechanical machining is sharply increased, and the application range of the material is greatly limited. Moreover, the research on how to improve the mechanical performance of the MM′X functional material has not been reported until now.

In conclusion, it's urgent for those skilled in this field to develop a novel MM′Y functional material with good mechanical properties.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the shortcomings in the prior art by providing an MM′X—Y metal composite functional material and a preparation method thereof. According to the method of the present invention, an MM′X—Y metal composite functional material with an excellent mechanical performance and ferromagnetic martensitic transition can be prepared. The prepared material possesses a high magnetic refrigeration performance and a wide application range.

To achieve the above purpose, the present invention adopts the following technical solution:

An MM′X—Y metal composite functional material, comprising the following components in percentage by volume:

A% of M_(a)M′_(b)X_(c) and B% of Y, wherein each of M and M′ is any one element of a transition group or an alloy of more than one element, X is any one element of IIIA group or IVA group or an alloy of more than one element, and Y is any one element of IB group, IIB group, IIA group or IVA group, or an alloy of more than one element, wherein the value range of a, b and c is 0.8-1.2, and the sum of A% and B% is 100%.

In another aspect of the present invention, A% is 50%-95%, and B% is 5%-50%.

In another aspect of the present invention, A% is 60%-90%, and B% is 10%-40%.

A preparation method of the MM′X—Y metal composite functional material, comprising the steps of:

-   -   1) Preparing raw materials according to the chemical formula of         M_(a)M′_(b)X_(c);     -   2) Feeding the prepared raw materials into a smelting furnace,         vacuuming the furnace and cleansing the furnace by argon;         subsequently, smelting the prepared raw materials under the         protection of argon, thereby obtaining the M_(a)M′_(b)X_(c)         alloy;     -   3) Vacuuming and annealing the M_(a)M′_(b)X_(c) alloy;     -   4) Respectively crushing and grinding the vacuumed and annealed         M_(a)M′_(b)X_(c) alloy and Y material; after screening,         obtaining powders;     -   5) Respectively measuring out the powder of M_(a)M′_(b)X_(c)         alloy with a volume percentage of A%, and the powder of Y         material with a volume percentage of B%; subsequently, mixing         them uniformly;     -   6) Adopting a pressing formation method to press the uniformly         mixed powder under magnetic field, thereby obtaining the formed         material;     -   7) Curing the formed material, thereby obtaining the MM′X metal         composite functional material.

In another aspect of the present invention, when M or M′ is Mn, Mn is excessively added according to the atomic ratio of 1%-10% for compensating its volatile and burning losses during the preparation process, thereby obtaining the single phase.

In another aspect of the present invention, when M or M′ is Mn, Mn is excessively added according to the atomic ratio of 2%-5%.

In another aspect of the present invention, the pressure in the smelting furnace is controlled to be smaller than or equal to 3×10⁻³ Pa after being vacuumed. The smelting temperature is higher than 1300° C., and the smelting time is 0.5-10 minutes.

In another aspect of the present invention, the pressure in the smelting furnace is 2×10⁻³-10⁻³ Pa after being vacuumed. The smelting temperature is 1300-1700° C., and the smelting time is 2-3 minutes.

In another aspect of the present invention, the vacuuming and annealing temperature is 600-1100° C., and the time is 1-30 days.

In another aspect of the present invention, the vacuuming and annealing temperature is 700-900° C., and the time is 5-15 days.

In another aspect of the present invention, the crushing method comprises one or any combination of the following methods including grinding, vibration grinding, rolling grinding, ball milling and jet milling, etc. The screen is a standard screen with a mesh size greater than 10 mesh, and the particle size of the powder is smaller than 2 mm.

In another aspect of the present invention, the screen is a standard screen with a mesh size of 100-300 mesh, and the particle size of the powder is 0-0.2 mm.

In another aspect of the present invention, the pressing formation is to press the powder into a required size or shape through a rolling method, a mold pressing method, an extrusion method, a powder injection forming method or a discharge plasma sintering method. During the process of the pressing formation, the pressure is 300-1500 Mpa, the temperature is 0-900° C., the time is 1-240 minutes and the intensity of the magnetic field is 0-5 T.

In another aspect of the present invention, during the process of the pressing formation, the pressure is 600-1000 MPa, the temperature is 0-500° C., the time is 5-60 minutes and the intensity of the magnetic field is 0-2 T.

In another aspect of the present invention, the curing temperature is 0-900° C. and the curing time is 1-15 days.

In another aspect of the present invention, the curing temperature is 0-500° C. and the curing time is 2-7 days.

Compared with the prior art, the present invention has the following advantages:

First, the present invention provides a novel MM′X—Y metal composite functional material; second, the mechanical performance of the MM′X—Y metal composite functional material prepared according to the present invention is far higher than the traditional MM′X material; third, the prepared MM′X—Y metal composite functional material has an ideal magnetothermal effect, thus can be used as a magnetic refrigeration material; fourth, the preparation method of the present invention can prepare MM′X—Y metal composite functional materials with any size and shape according to actual requirements; fifth, the preparation method of the present invention is simple, and can be easily operated and realized in industrial production.

BRIEF DESCRIPTION OF THE DRAWINGS

To clearly expound the technical solution of the present invention, the drawings and embodiments are hereinafter combined to illustrate the present invention. Obviously, the drawings are merely some embodiments of the present invention and those skilled in the art can associate themselves with other drawings without paying creative labor.

FIG. 1 is a topography diagram of the smelted Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) prepared according to embodiment 1 of the present invention;

FIG. 2 is a topography diagram of the smelted 70% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+30% In metal composite functional material prepared according to embodiment 1 of the present invention;

FIG. 3 is a stress-strain curve graph of the 70% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+30% In metal composite functional material prepared according to embodiment 1 of the present invention;

FIG. 4 is a diagram showing the temperature dependence of ΔS of the 70% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+30% In metal composite functional material prepared according to embodiment 1 of the present invention in different magnetic fields;

FIG. 5 is a stress-strain curve graph of the 75% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+25% In metal composite functional material prepared according to embodiment 2 of the present invention;

FIG. 6 is a stress-strain curve graph of the 80% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+20% In metal composite functional material prepared according to embodiment 3 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Drawings and detailed embodiments are combined hereinafter to elaborate the technical principles of the present invention.

Embodiment 1

As shown in FIGS. 1-4, the present invention discloses a 70% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+30% In metal composite functional material and a preparation method thereof.

The preparation method of the 70% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+30% In metal composite functional material, comprising the steps of:

-   -   1) Preparing raw materials according to the chemical formula of         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5), wherein the raw materials         are commercially available metals including Mn, Fe, Ni, Si and         Ge with a purity higher than 99.9 wt. %, and Mn is excessively         added according to the atomic ratio of 5% for compensating its         volatile and burning losses during the preparation process;     -   2) Adopting an electric arc smelting method; feeding the         prepared raw materials into a smelting furnace, vacuuming the         smelting furnace until the pressure intensity reaches 2×10⁻³ Pa,         and cleansing the furnace by argon; subsequently, smelting the         prepared raw materials at a temperature of 1500° C. for 3         minutes under the protection of argon, thereby obtaining the         cast ingot Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5);     -   3) Placing the Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) into a quartz         tube with a vacuum degree of 5×10⁻³ Pa, and annealing at a         temperature of 850° C. for 7 days;     -   4) Respectively crushing and grinding the vacuumed and annealed         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) and metal In by using an         agate mortar, and screening out the irregular powder with a size         smaller than 0.1 mm according to the screening standard of         150-mesh;     -   5) Respectively measuring out the         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) powder with a volume         percentage of 70%, and the In powder with a volume percentage of         30%; subsequently, mixing them uniformly;     -   6) Pressing the uniformly mixed powder at the condition of         150° C. and 900 MPa for 5 minutes under zero magnetic field,         thereby obtaining a cylindrical 70%         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5+)30% In metal composite         functional material with a diameter of 10 mm;     -   7) Curing at a temperature of 150° C. for 7 days, thereby         obtaining the 70% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+30% In         metal composite functional material, namely, the product of this         embodiment.

The morphology of the smelted Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) sample prepared in embodiment 1 is shown in FIG. 1. As can be seen from FIG. 1, after a traditional smelting process, the sample undergoes a martensitic transition when being cooled from a high temperature to a room temperature. The sample is crumbled due to the huge internal stress generated in the transition process, making the forming and mechanical machining become extremely difficult. The application range of the functional material is thus greatly limited. The morphology of the product of embodiment 1 is shown in FIG. 2. As can be seen, it can be easily formed and processed, effectively solving the prior technical problems.

For the mechanical performance of the traditional crumbled MM′X alloy is extremely poor, the stress-strain curve test cannot be carried out. In contrast, the mechanical performance of the product prepared in embodiment 1 is remarkably improved so that the test can be easily performed. The stress-strain curve of the prepared product can be tested by using a WDW200D type microcomputer control universal material tester. As shown in FIG. 3, after being tested, the compressive strength of the prepared product is 45 MPa, and the corresponding strain is 9.2%.

After measuring the isothermal magnetization curve (M-H curve) of the prepared product by using a magnetic measurement system (Versalab Free Measurement System developed by Quantum Design, Inc.), the magnetic entropy change ΔS can be calculated from the isothermal magnetization curve according to Maxwell's relation ΔS=∫₀ ^(H)(∂M/∂T)_(H)dH . FIG. 4 shows the temperature dependence of ΔS of the prepared product in different magnetic fields. As can be seen, when the transition temperature is near 311K, the maximum value of the magnetic entropy change appears. When the intensity of the magnetic field respectively varies from 0 to 1 T, 0 to 2 T, and 0 to 3 T, the maximum magnetic entropy change of the sample is respectively 4.5 J/kgK, 9.9 J/kgK, and 15.3 J/kgK. Presently, a magnetic field at intensity of 2 T can be obtained by utilizing the permanent magnet NdFeB. Therefore, the magnetic entropy changes of the material when the magnetic intensity varies from 0 to 2 T attracts more attentions. Under such a circumstance, the maximum value of the magnetic entropy change (9.9 J/kgK) of the prepared product is much greater than that (when the magnetic intensity is 2 T, the magnetic entropy change is 5.0 J/kgK) of the traditional room-temperature magnetic refrigeration material Gd. It means that the product of the aforesaid embodiment can be used as a better room-temperature functional material.

Embodiment 2

As shown in FIG. 5, the present invention discloses a 75% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+25% In metal composite functional material and a preparation method thereof. The preparation method of the 75% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+25% In metal composite functional material, comprising the steps of:

-   -   1) Preparing raw materials according to the chemical formula of         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5), wherein the raw materials         are commercially available metals including Mn, Fe, Ni, Si and         Ge with a purity higher than 99.9 wt. %, and Mn is excessively         added according to the atomic ratio of 5% for compensating its         volatile and burning losses during the preparation process;     -   2) Adopting an electric arc smelting method; feeding the         prepared raw materials into a smelting furnace, vacuuming the         smelting furnace until the pressure intensity reaches 2.5×10⁻³         Pa, and cleansing the furnace by argon; subsequently, smelting         the prepared raw materials at a temperature of 1700° C. for 2         minutes under the protection of argon, thereby obtaining the         cast ingot Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5);     -   3) Placing the Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) into a quartz         tube with a vacuum degree of 5×10⁻³ Pa, and annealing at a         temperature of 850° C. for 8 days;     -   4) Respectively crushing and grinding the vacuumed and annealed         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) and metal In by using an         agate mortar, and screening out the irregular powder with a size         smaller than 0.07 mm according to the screening standard of         200-mesh;     -   5) Respectively measuring out the         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) powder with a volume         percentage of 75%, and the In powder with a volume percentage of         25%; subsequently, mixing them uniformly;     -   6) Pressing the uniformly mixed powder at the condition of         140° C. and 900 MPa for 10 minutes under zero magnetic field,         thereby obtaining a cylindrical 75%         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+25% In metal composite         functional material with a diameter of 10 mm;     -   7) Curing at a temperature of 500° C. for 7 days, thereby         obtaining the 75% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+25% In         metal composite functional material.

The stress-strain curve of the 75% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+25% In metal composite material can be tested by using a WDW200D type microcomputer control universal material tester. As shown in FIG. 5, after being tested, the compressive strength of the prepared product is 48 MPa, and the corresponding strain is 15.6%. Meanwhile, the magnetic test shows that the magnetothermal effect of the prepared product of embodiment 2 is better than that of the traditional room-temperature magnetic refrigeration material Gd.

Embodiment 3

As shown in FIG. 6, the present invention discloses an 80% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+20% In metal composite functional material and a preparation method thereof. The preparation method of the 80% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+20% In metal composite functional material, comprising the steps of:

-   -   1) Preparing raw materials according to the chemical formula of         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5), wherein the raw materials         are commercially available metals including Mn, Fe, Ni, Si and         Ge with a purity higher than 99.9 wt. %, and Mn is excessively         added according to the atomic ratio of 3% for compensating its         volatile and burning losses during the preparation process;     -   2) Adopting an electric arc smelting method; feeding the         prepared raw materials into a smelting furnace, vacuuming the         smelting furnace until the pressure intensity reaches 3×10⁻³ Pa,         and cleansing the furnace by argon; subsequently, smelting the         prepared raw materials at a temperature of 1700° C. for 2         minutes under the protection of argon, thereby obtaining the         cast ingot Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5);     -   3) Placing the Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) into a quartz         tube with a vacuum degree of 5×10⁻³ Pa, and annealing at a         temperature of 750° C. for 15 days;     -   4) Respectively crushing and grinding the vacuumed and annealed         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5) and metal In by using an         agate mortar, and screening out the irregular powder with a size         smaller than 0.1 mm according to the screening standard of         150-mesh;     -   5) Respectively measuring out the         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0. 5) powder with a volume         percentage of 80%, and the In powder with a volume percentage of         20%; subsequently, mixing them uniformly;     -   6) Pressing the uniformly mixed powder at the condition of         140° C. and 900 MPa for 6 minutes in zero magnetic field,         thereby obtaining a cylindrical 80%         Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+20% In metal composite         functional material with a diameter of 10 mm;     -   7) Curing at a temperature of 500° C. for 7 days, thereby         obtaining the 80% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+20% In         metal composite functional material.

The stress-strain curve of the 80% Mn_(0.6)Fe_(0.4)NiSi_(0.5)Ge_(0.5)+20% In metal composite material can be tested by using a WDW200D type microcomputer control universal material tester. As shown in FIG. 6, after being tested, the compressive strength of the prepared product is 41 MPa, and the corresponding strain is 14.9%.

Embodiment 4

The present invention discloses a 60% MnCoCu_(0.08)Ge_(0.92)+40% Sn metal composite functional material and a preparation method thereof. The preparation method of the 60% MnCoCu_(0.08)Ge_(0.92)+40% Sn metal composite functional material, comprising the steps of:

-   -   1) Preparing raw materials according to the chemical formula of         MnCoCu_(0.08)Ge_(0.92), wherein the raw materials are         commercially available metals including Mn, Co, Cu and Ge with a         purity higher than 99.9 wt. %, and Mn is excessively added         according to the atomic ratio of 3% for compensating its         volatile and burning losses during the preparation process;     -   2) Adopting an electric arc smelting method; feeding the         prepared raw materials into a smelting furnace, vacuuming the         smelting furnace until the pressure intensity reaches 2×10⁻³ Pa,         and cleansing the furnace by argon; subsequently, smelting the         prepared raw materials at a temperature of 1600° C. for 3         minutes under the protection of argon, thereby obtaining the         cast ingot MnCoCu_(0.8)Ge_(0.92);     -   3) Placing the MnCoCu_(0.08)Ge_(0.92) into a quartz tube with a         vacuum degree of 5×10⁻³ Pa, and annealing at a temperature of         800° C. for 15 days;     -   4) Respectively crushing and grinding the vacuumed and annealed         MnCoCu_(0.08)Ge_(0.92) and metal Sn by using a jet mill, and         screening out the irregular powder with a size smaller than 0.05         mm according to the screening standard of 300-mesh;     -   5) Respectively measuring out the MnCoCu_(0.08)Ge_(0.92) powder         with a volume percentage of 60%, and the Sn powder with a volume         percentage of 40%; subsequently, mixing them uniformly;     -   6) Pressing the uniformly mixed powder at the condition of room         temperature and 960 MPa for 15 minutes in a magnetic field at         intensity of 1.5 T, thereby obtaining a cylindrical 60%         MnCoCu_(0.08)Ge_(0.92)+40% Sn metal composite functional         material with a diameter of 10 mm;     -   7) Curing at a temperature of 500° C. for 7 days, thereby         obtaining the 60% MnCoCu_(0.08)Ge_(0.92)+40% Sn metal composite         functional material, namely, the product of this embodiment.

Embodiment 5

The present invention discloses a 75% Mn_(0.95)CoGe_(0.9)Si_(0.1)+25% InSn metal composite functional material and a preparation method thereof. The preparation method of the 75% Mn_(0.95)CoGe_(0.9)Si_(0.1)+25% InSn metal composite functional material, comprising the steps of:

-   -   1) Preparing raw materials according to the chemical formula of         Mn_(0.95)CoGe_(0.9)Si_(0.1), wherein the raw materials are         commercially available metals including Mn, Go, Ge and Si with a         purity higher than 99.9 wt. %, and Mn is excessively added         according to the atomic ratio of 4% for compensating its         volatile and burning losses during the preparation process;     -   2) Adopting an electric arc smelting method; feeding the         prepared raw materials into a smelting furnace, vacuuming the         smelting furnace until the pressure intensity reaches 3×10⁻³ Pa,         and cleansing the furnace by argon; subsequently, smelting the         prepared raw materials at a temperature of 1400° C. for 3         minutes under the protection of argon, thereby obtaining the         cast ingot Mn_(0.95)COGe_(0.9)Si_(0.1);     -   3) Placing the Mn_(0.95)CoGe_(0.9)Si_(0.1) into a quartz tube         with a vacuum degree of 5×10⁻³ Pa, and annealing at a         temperature of 900° C. for 5 days;     -   4) Respectively crushing and grinding the vacuumed and annealed         Mn_(0.95)CoGe_(0.9)Si_(0.1) and metal InSn by using a high         energy ball mill, and screening out the irregular powder with a         size smaller than 0.06 mm according to the screening standard of         250-mesh;     -   5) Respectively measuring out the Mn_(0.95)CoGe_(0.9)Si_(0.1)         powder with a volume percentage of 75%, and the InSn powder with         a volume percentage of 25%; subsequently, mixing them uniformly;     -   6) Pressing the uniformly mixed powder at the condition of         800° C. and 600 MPa for 15 minutes in zero magnetic field,         thereby obtaining a cylindrical 75%         Mn_(0.95)CoGe_(0.9)Si_(0.1)+25% InSn metal composite functional         material with a diameter of 10 mm;     -   7) Curing at a temperature of 500° C. for 7 days, thereby         obtaining the 75% Mn_(0.95)CoGe_(0.9)Si_(0.1)+25% InSn metal         composite functional material, namely, the product of this         embodiment.

The description of above embodiments allows those skilled in the art to realize or use the present invention. Without departing from the spirit and essence of the present invention, those skilled in the art can combine, change or modify correspondingly according to the present invention. Therefore, the protective range of the present invention should not be limited to the embodiments above but conform to the widest protective range which is consistent with the principles and innovative characteristics of the present invention. Although some special terms are used in the description of the present invention, the scope of the invention should not necessarily be limited by this description. The scope of the present invention is defined by the claims. 

1. An MM′X—Y metal composite functional material, comprising the following components in percentage by volume: A% of M_(a)M′_(b)X_(c) and B% of Y, wherein each of M and M′ is any one element of a transition group or an alloy of more than one element, X is any one element of IIIA group or IVA group or an alloy of more than one element, and Y is any one element of IB group, IIB group, IIA group or IVA group, or an alloy of more than one element, wherein the value range of a, b and c is 0.8-1.2, and the sum of A% and B% is 100%.
 2. The MM′X—Y metal composite functional material of claim 1, wherein A% is 50%-95%, and B% is 5%-50%.
 3. The MM′X—Y metal composite functional material of claim 1, wherein A% is 60%-90%, and B% is 10%-40%.
 4. A preparation method of the MM′X—Y metal composite functional material, comprising the steps of: 1) Preparing raw materials according to the chemical formula of M_(a)M′_(b)X_(c); 2) Feeding the prepared raw materials into a smelting furnace, vacuuming the furnace and cleansing the furnace by argon; subsequently, smelting the prepared raw materials under the protection of argon, thereby obtaining the M_(a)M′_(b)X_(c) alloy; 3) Vacuuming and annealing the M_(a)M′_(b)X_(c) alloy; 4) Respectively crushing and grinding the vacuumed and annealed M_(a)M′_(b)X_(c) alloy and Y material; after screening, obtaining powders; 5) Respectively measuring out the powder of M_(a)M′_(b)X_(c) alloy with a volume percentage of A%, and the powder of Y material with a volume percentage of B%; subsequently, mixing them uniformly; 6) Adopting a pressing formation method to press the uniformly mixed powder under magnetic field, thereby obtaining the formed material; 7) Curing the formed material, thereby obtaining the MM′X metal composite functional material.
 5. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein when M or M′ is Mn, Mn is excessively added according to the atomic ratio of 1%-10% for compensating its volatile and burning losses during the preparation process, thereby obtaining the single phase.
 6. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein when M or M′ is Mn, Mn is excessively added according to the atomic ratio of 2%-5%.
 7. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the pressure in the smelting furnace is controlled to be smaller than or equal to 3×10⁻³ Pa after being vacuumed, wherein the smelting temperature is higher than 1300° C., and the smelting time is 0.5-10 minutes.
 8. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the pressure in the smelting furnace is 2×10⁻³-3×10⁻³ Pa after being vacuumed, wherein the smelting temperature is 1300-1700° C., and the smelting time is 2-3 minutes.
 9. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the vacuuming and annealing temperature is 600-1100° C., and the time is 1-30 days.
 10. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the vacuuming and annealing temperature is 700-900° C., and the time is 5-15 days.
 11. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the crushing method comprises one or any combination of the following methods including grinding, vibration grinding, rolling grinding, ball milling and jet milling, etc., wherein the screen is a standard screen with a mesh size greater than 10 mesh, and the particle size of the powder is smaller than 2 mm.
 12. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the screen is a standard screen with a mesh size of 100-300 mesh, and the particle size of the powder is 0-0.2 mm.
 13. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the pressing formation is to press the powder into a required size or shape through a rolling method, a mold pressing method, an extrusion method, a powder injection forming method or a discharge plasma sintering method, wherein during the process of the pressing formation, the pressure is 300-1500 Mpa, the temperature is 0-900° C., the time is 1-240 minutes and the intensity of the magnetic field is 0-5 T.
 14. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein during the process of the pressing formation, the pressure is 600-1000 MPa, the temperature is 0-500° C., the time is 5-60 minutes and the intensity of the magnetic field is 0-2 T.
 15. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the curing temperature is 0-900° C. and the curing time is 1-15 days.
 16. The preparation method of the MM′X—Y metal composite functional material of claim 4, wherein the curing temperature is 0-500° C. and the curing time is 2-7 days. 